The invention relates to a roller forming device for forming or marking a material provided with geometric elements, in particular holes. This type of roller forming device is designed with at least one forming roller and at least one counter element, in particular a counter roller or a counter table, wherein a gap roll is configured between the forming roller and the counter element for carrying through the material, and wherein the forming roller has a molding structure on its cylindrical surface, which molds the material when the material runs through the roll gap.
According to the prior art, installation rails are typically fabricated in the following process sequence: 1. Straightening of the strip in a straightening machine; 2. Punching geometric elements designed as holes and, if applicable, introducing additional geometric elements such as impressions, pockets, etc., which must have a defined position with respect to the hole pattern, on a mechanical or hydraulic sheet metal forming press; 3. Roll profiling of the perforated strip into a rail on a roll profiling unit; and 4. Cutting the rails to the desired length on a revolving separator.
In the case of this process sequence, the additional geometric elements generated by the sheet metal forming press run through the downstream roll profiling unit. Under some circumstances, this may result in the additional geometric elements being deformed by the subsequent forming operation on the roll profiling unit. In addition, this process chain may restrict the geometric freedom for the additional geometric elements to be introduced, because the additional geometric elements require appropriate clearances in the subsequent sets of rollers on the roll profiling unit for unobstructed passage, which is not always possible.
It is also known to roll structures onto a strip material.
The object of the invention is disclosing a roller forming device for forming an elongate metal material, which provides an especially large degree of geometric freedom and which permits geometric elements such as impressions, pockets, etc., to be precisely formed in an especially simple and reliable manner.
A roller forming device according to the invention for forming or marking a material provided with geometric elements is characterized in that the forming roller has carrier elements for an engagement with the geometric elements, in particular for an engagement in the geometric elements of the material running through the roll gap.
A first basic idea of the invention may be seen as no longer generating the additional geometric elements by means of the sheet metal forming press, but introducing these through a rolling process, which can be carried out on a roll profiling unit downstream from the sheet metal forming press. In particular, this procedure makes it possible to introduce the additional geometric elements only after the forming steps, which would produce a deformation of these elements, and thereby enables the additional geometric elements to be formed especially precisely and with an especially high level of geometric freedom.
The invention further recognizes that an introduction of the additional geometric elements through a driven forming roller running at a constant speed of rotation could be associated with an unsatisfactory result under some circumstances. In the case of known forming devices, a fluctuating elongation and the resulting deviation in the desired rail length is often corrected on the press by adapting the feed rate, which can produce fluctuations in the spacing of the holes from one another. If a constant speed of rotation were to be used in this case, then the fluctuations in the spacing of the holes would produce an undesired offset of the additional geometric elements from the holes.
In order to overcome this potential disadvantage, the invention teaches a non-driven forming roller, i.e., a forming roller that is not provided with a drive, that has carrier elements, which may engage on the first geometric elements, i.e., in particular the holes, so that the forming roller is carried along by the holes in the metal material. Through contact between the carrier element and the edge of the respective hole trailing in the direction of rolling, the carrier elements bring about a rotation of the entire forming roller in accordance with the throughput speed of the material. A mechanical synchronization of the forming roller with the previous introduced hole pattern is hereby realized in an especially simple manner, which reliably guarantees a defined position of the to-be-introduced additional geometric element with the edge of the hole without requiring involved measuring and control technology.
According to the invention, several rollers designed according to the invention may be provided, each of which may then cooperate with a counter roller. According to the invention, the material may be in particular a metallic material, a flat material and/or a strip material, preferably a sheet metal strip. The carrier elements are expediently designed to be peg-shaped.
The roller forming device according to the invention is preferably used for forming a material provided with a plurality of identical geometric elements. The geometric elements are preferably arranged at least approximately equidistantly on the material. The geometric elements may preferably be holes, in particular elongated holes, which extend in the direction of rolling. The geometric elements, however, may also be, for example, raised tabs, lateral recesses or notches, sharp-edge pockets or folds. The invention may advantageously be used in every application in which a subsequent introduction of additional geometric elements that are not freely positionable in a linear material is required where a preceding process step already introduced first geometric elements on which the forming roller according to the invention may catch and synchronize via the carrier elements. According to the invention, the carrier elements are provided in addition to the molding structure. According to the invention, the material provided with the first geometric elements is conveyed to the roller forming device, where it is then provided with the additional geometric elements by the molding structure.
In particular with respect to geometric freedom, it is advantageous that the carrier elements are disposed on the cylindrical surface of the forming roller. It is hereby possible to form additional geometric elements with the forming roller also in the areas which are located between the first geometric elements.
In addition, according to the invention it may be provided that the counter roller has at least one recess for the carrier elements. A reliable operation is also possible hereby even in the case of especially long carrier elements.
A further preferred embodiment of the invention is that the counter roller is mechanically coupled with the forming roller so that a rotation of the forming roller produces a rotation of the counter roller. This type of coupling may be realized, for example, via gear wheels, which are attached on the face side on both rollers.
Moreover, it may be advantageous that the counter roller have a molding structure on its cylindrical surface, which molds the material when the material runs through the roll gap. According to this embodiment, geometric elements may be introduced on the material from both sides thereby further increasing the geometric freedom.
It is especially preferred that the forming roller have at least one run-through angular position, in which the forming roller is spaced apart from the material running through the roll gap, in particular on the molding structure and on the carrier elements of the forming roller. In this run-through angular position, the forming roller is not in contact with the material passing through on its molding structure or on its carrier elements. This type of embodiment of the forming roller makes it possible to stop the roller rotation temporarily or at least slow it down, while the material continues to be moved through the roll gap at a continuous feed rate. As a result, the roller forming device according to the invention may be used in an advantageous manner also in the case of materials in which the spacing of the first geometric elements, i.e., the hole spacing in particular, varies with the time. This is because, for example, a temporarily greater spacing can then be compensated for by a temporarily longer stop of the roller rotation at the run-through angular position, for example. The invention thereby permits an especially high level of precision in the forming process even with varying hole spacing, because it always guarantees a defined position of the to-be-introduced geometric element with an edge of the hole through the intermittently reduced speed of rotation of the forming roller even in the case of fluctuations in the hole spacing. A run-through angular position in which the forming roller is spaced apart from the material running through the roll gap may be made available, for example, in that the carrier elements are smaller in terms of their dimension in the direction of rolling than the hole length. In this case, a run-through of the material relative to the roller may then be possible if the carrier element is situated in the hole, i.e., in the time interval in which the carrier element in the hole moves through the hole. The run-through angular position may also be realized, however, by a sufficiently great angular distance from the adjacent projections on the cylindrical surface of the forming roller.
It is also advantageous that a brake is provided for braking the forming roller. Such a brake may guarantee, for example, that, after pulling a carrier element out of a hole and/or reaching the run-through angular position, the forming roller brakes instead of continuing to rotate unabated due to its inertia so that an uncontrolled striking of the subsequent carrier element in the hole and/or an undesired premature engagement of the subsequent molding structure may be prevented, for example.
Another preferred embodiment of the invention is that at least one of the carrier elements has a friction reducer on its tip for preventing friction between the carrier element and the material. The friction reducer may have, for example, at least one sliding element or at least one roller. This further development has recognized that under some circumstances there is a risk that the material will get scratched by an edge of the peg-shaped carrier elements, and in particular specifically when the forming roller stops abruptly after pulling the carrier element out of the hole, e.g., because of a brake being applied strongly. The friction reducer is able to guarantee that the linear material is able to run through in this roller position as much as possible without any damage.
It is especially preferred that the forming roller is designed to be multi-piece with at least one first roller part on which at least one portion of the molding structure is disposed, and with at least one second roller part on which at least one portion of the carrier elements is disposed, wherein the first roller part and the second roller part can be rotated relative to one another. For example, it is possible to hereby adjust the position of the additional geometric elements formed by the forming roller with respect to the hole pattern. Therefore, according to the invention, both roller parts are able to be rotated around the axis of rotation of the forming roller relative to one another. The two roller parts may in particular be designed to be disk-shaped. The forming roller may also have more than two roller parts that are rotatable relative to one another.
The invention also relates to an apparatus for forming a material, having a device, in particular a press, for introducing geometric elements in the material, and a roller forming device according to the invention for forming the material provided with the geometric elements. Because the geometric elements are preferably holes, the press may be a stamping press in particular. According to the invention, the roller forming device is downstream from the stamping press in terms of the process. The roller forming device may also have additional forming rollers, in particular bending rollers, and be a part of a roll profiling unit. The apparatus according to the invention is preferably used for producing installation rails. Since, according to the invention, the dimensioning of the roller forming device, in particular its forming roller, may depend upon the dimensioning of the material to be formed, the invention may also include a forming arrangement made of a material provided with geometric elements according to the invention and the roller forming device according to the invention for forming the material provided with the geometric elements.
The invention will be explained in greater detail in the following on the basis of preferred exemplary embodiments, which are depicted schematically in the figures.